Very good post by Owenmpk. I am a geotechnical engineer, and am also astonished by the variety of stone that is called "granite". Unfortunately the geological definition of granite is not followed by the companies that sell the product. Anything with mica, biotite and quartz is apparently classed as granite, regardless whether it is metamorphic or igneous. Not that the user really needs to care exactly what type of rock it is, but it does make a huge difference in terms of stain resistance, hardness, and overall durability what type of minerals are in the rock. Unfortunately, unless you have geological training, you aren't going to know. The moral is to bring a geologist with you when you select your slab.
I have "granite" counters, although in truth they are gneiss. Very beautiful, extremely durable, and no we never sealed them, I don't want toxic chemicals on my food preparation surface. The stone can scratch, however this has not been a problem for us. We also spill wine regularly, as well as many other things, and we clean it up immediately. No stains of any kind.
I have no problem with Corian, soapstone, formica, tiles, wooden counters, concrete counters, or any other kind of material. Just make sure you understand fully the properties of the material, the maintenance requirements, and your ability to fix the surface if it is damaged. Nothing is perfect, else everyone would use it.